Metaphosphate complexes of diphtheria and tetanus toxoids and purifying said toxoids



United States l atent METAPHOSPHATE comLExEs or DIPHrHERiA AND TETANUS roxoms AND PURlFYlNG SAID Toxoms Morris B. Jacobs, Bayside, N. Y., assignor to American Home Products Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application March 15, 1954, Serial No. 416,405

Claims. (Cl. 167-78) This application is a continuationin-part of my previously filed application for a Method for the Purification of Biological Substances, Serial No. 216,089, filed March 16, 1951.

This invention relates to a method for the simultaneous purification and concentration of materials such as toxoids, toxins, and the like and to the preparation of ;novel products therefrom.

Despite the many methods and variations of methods 'which have been proposed for the concentration and purification of toxoids, toxins, and the like, as has been -reviewed by G. Norlin, Acta Path. Microbiol. Scand. .24, 505 (1947) and by M. B. Jacobs, I. Am. Phann. .Assoc., Sci. Ed., 39, 466 (1950), none has achieved -widespread acceptance and crude bacterial toxin filtrates, :and crude detoxified bacterial filtrates are still employed for immunization. There are two principal reasons for *the use of such crude preparations. First the methods of purification are time-consuming and the losses in recovery are large. Secondly the equipment, comprising refrigerated boxes, chambers, or rooms, and refrigerated centrifuges necessary for certain methods is relatively :so expensive as to preclude their general use.

It is an object of this invention to purify toxoids, toxins, and the like, by separating them from crude :filtrates such as crude bacterial filtrates, crude detoxified bacterial filtrates, and the like.

it is a further object of this invention to concentrate -the toxoids, toxins, and the like simultaneously with purifying said toxoids, toxins, and the like and thus pro- 'vide a concentrated purified product which can be used --in the preparation of polyantigens, viz., mixtures of :antigens such as combinations of tetanus toxoids, diphtheria toxoids, and pertussis vaccines, or for other similar preparations.

In general, my method of simultaneously purifying :and concentrating biological substances of the class con- :sisting of toxoids, toxins, and the like comprises adding :at least one polymeric phosphate acid substance which can form a toxoid or toxin precipitate. For example, I may use such substances as metaphosphoric acid, or lhexametaphosphoric acid, or tripolyphosphoric acid, or other toxoid or toxin precipitating polymeric phosphate :acid forming a resultant toxoid or toxin polymeric phosphate precipitate, thereby precipitating the desired toxoids or toxins, and the like, and thereafter separating said gprecipitated toxoid or toxin polymeric phosphate com- ;plex by centrifugation, filtration, or other conventional method. Following the above procedure, I dissolve the :said precipitated complex in a buifer solution of a volume materially reduced from that of the original solution, whereupon a purified concentrate is obtained which is useful as an antigenic material when properly diluted or 'from which the polymeric phosphate ion can be removed by conventional methods such as dialysis or an ion ex- -change procedure before being used as an antigenic ma 'terial.

2,772,292 Patented Nov. 27, 1956 toxin, or like substances can be used directly, as in the case of the addition of a solution of metaphosphoric acid, but I prefer to use a non-toxic soluble salt of such acids as for instance sodium hexametaphosphate or sodium tripolyphosphate or related phosphates or mixtures of such phosphates and generate the acid in site by the addition of hydrochloric acid or sulfuric acid or other non-toxic acid. The terms metaphosphate and hexa metaphosphate are commonly used and are herein ln= tended to refer to soluble vitreous alkali-metal phosphates consisting of materials having an MzO/PzOe mole ratio lying between 1.0 and 1.66, where M signifies an alkali metal; true cyclic metaphosphates having a mole ratio of 1.0, tripolyphosphate having a mole ratio of 1.66 and higher straight chain polyphosphates lying between these limits. (See Von Wazer, Ind. & Eng. Chem. 41, 189 (1949); Von Wazer, I. A. C. S., 72, 647 (1950); and Partridge, Chem. & Eng. News, 27, 214 (1949.) The precipitation can be carried out at room temperature but it is preferable with toxoids prepared with natural media to carry out the precipitation placed in each of two centrifuge cups.

The polymeric phosphate used to precipitate the toxoid, -l

at somewhat higher temperatures of the order of 38 C. to 43 C. Bufier solutions such as mixtures of potassium dihydrogen phosphate and disodium hydrogen phosphate or of sodium citrate and sodium hydroxide which can give a pH of about 8, or solutions of salts which have buifering action such as sodium citrate which can give solutions having a pH of about 8 are preferable for the solution of the precipitated toxoids, toxins, and like materials.

By way of illustration but not as a limitation of my invention, the following examples of my invention are detailed.

Example I One hundred and sixty milliliters of diphtheria toxoid were placed in each of two centrifuge cups. This diphtheria toxoid contained 40 flocculation units per ml. and had 4.1 mg. of nitrogen per ml. (Flocculation units per ml. (Lil/ml.) are used as a measure of the potency of a toxoid or toxin.) To each cup was added 32 ml. of 10 percent sodium hexametaphosphate aqueous solution, whereupon the two mixtures were mixed. To each resulting mixture, 32 ml. of 1 normal hydrochloric acid was added and again the mixtures were stirred. The resulting compositions were allowed to stand at room temperature until the precipitates which formed had flocculated. The cups were then placed in a centrifuge and were whirled at 2775 revolutions per minute for 5 minutes to pack the precipitates. The supernatant liquids were poured oif, the cups were inverted and allowed to drain free from any remaining supernatant liquid and the precipitates which were packed at the bottom of the cups were dissolved in 10 ml. of a sodium citratesodium hydroxide buffer solution of pH 8.0. Then this solution was tested for flocculation units, it contained 1044 units per ml., a concentration 26 times that of the crude material. The nitrogen content of the concentrate was 2.29 mg. per ml. On the basis of the original nitrogen content of 10 flocculation units per mg. of nitrogen, the concentrate contained 456 flocculation units per mg. of nitrogen, signifying that a purification of 45.6 times was achieved.

Example 11 One hundred and sixty ml. of diphtheria toxoid were This diphtheria toxoid contained 40 Lf./ml. and had 4.1 mg. of nitrogen per ml. The method as detailed in Example I was followed except that to each cup 40 ml. of 1 normal hydrochloric acid was added instead of 32 ml. The precipitates were dissolved in 10 ml. of sodium citrate- I flask. I

, nietaphosphate was added and after iiii normal sulfuric acid'was added. Apr".

' resented'a volume concentration of 30'ti rii'es.

sodium hydroxide bufier solution of pH '8 and gave a rsuet wh 0n u d .2.80 LfJmL' Th n trog content was 2.60 rug/ml. This represented a concentration of 32 times that of the crude material and a purification of 49 times that of the original material.

7 Example III Onehundred and sixty oiidiphtheria toxoid was placed into a centrifuge cup; This diphtheria toxoid contained 40'Lf./ml. and had 4.1 of nitrogen per at 2 77 5 revolutions per minute for 5 {ninutes'tb pack a r the precipitate iwhich had forrn ed. The Qsupe-rnatant liquid was poured omthe, was iuve fid to pe rmit fany', remaininglsupernatant liquid to drain 913?, and then the precipitate which was packed at gthe b ottom of the cup was-dissolvediinS ml. of 3 -perce n t sod ium; citrate f-f m -i 315d .2 1 .f in tr s a 'ii rft l- T e nt n a. sens m a a P ,.F a w s a EE Ei P Q of 5 times that'of the original crude material. a

' Example IV Six hundred'lml. of tetanus toiioidwas"placedin a v To this 120 ml. of 10percent sad sm page 0 "mg I20 'r'r'1lfof I p I itate formed almost iinrnediat'elyw This was gently suspended and the contents'of the flask was transferred to centrifuge cupsfor ceutrifugation. The centrifuge. enps 'w'ereaemoved from the centrifuge, the supernatant liquids were poured off, the cups were inverted to peiiiiit"them to drain thoroughly and the precipitates packed at 'the'bottom of the cups were diss'cil'ved'in a potassium dihydrogen phosphate-disodiurn hydrogenphosphatebiilierof pH 8 0 'byusing 5 ml. of buffer solution fo'uf'tirnes, passing each 5- ml. of buffer'solution from cup 'to'cup successively; A total of 20 ml. 'of buffer 'solution' wasmsed and the precipitates dissolved readily in this'solution. This rep- Eraniple' V 4a One hundred 'ml. of tetanus toxoidwas'placed imacentrifuge cup and to this 10ml. of'a freshly-prepared 25 percent solution of metaphosphorieacidwas added. A precipitate formed'in about -10 minutes. This precipitate' was collected by "centrifugation'andafterpour ing otfthe supernatant solution, allowing'the supernatant solution to drain off, the desired precipitated toxoid was dissolved in 5 ml; of'the phosphate pH 8'butfersolution mentionedin Example IV. This :represented a volume concentration"of"20 times that of the l o'riginalcrude tetanus toxoid. a

V i "Example: VI A" small amo nt of th solid texo'id "metaphosphate precipitate as prepared'in EXa uP e IV"was washed free offallimetaphosph'ate andg'recoiistituted in physiologic saline solutionlusing dilute Na'QH and H CI for adjnsnnent). 'sc'lutionjfg'ave nojqualitative test for iphb's'php'r'ous (co lorf test"with i ammonium'molybdate' re-' agent and be'nzidine' as described by Feiglin Spot Tests, 5

3rd ed., Elsev-ier Publishing Co.,'Inc;,Neuf York (1946);

' sensitivity one part per million). 7 After heating, prefer- 7 ably with acid, a positive phosphorus testwas obtained. fAfter' seven days'storageof the rneta'phosphate' toxoid' solutioninthe cold, these test 'res'ultsfwere-'identical.. 7

Itis;to 'be noted that the addition 'ofthe lfnoimal sulfuric acid 'or the lgnormal' hydrochloric"acid or the 11: normal acetic; acid wasinsufiicient to-"precipi'tateth'e 1 desired toxoid, toxin, orenzyine; or *like material *even onstanding'foi'ion'g periods. 7 V 1 76 to -an aqueous solution of said'toxoid The advantages of my novel method are many. By a method which can be performed with equipment .generally available in all chemical, pharmaceutical, immunochemical, and bacteriological laboratories, a manyfold concentration and purification of toxoids, toxins, and the like can be readily obtained. Z'I 'he products so obtained can be utilized in their concentrated form; as for instance in thepreparation of polyantigens, or they can be diluteri to 'make "fluid toxinor toxoid preparations .free. from the impurities present in the parent crude bacterial "filtrates, or they'can be converted into qalumprecipitated 'toxoids.

The scope of this invention is notfto be limited toa-the examples herein --disclosed since these are but the embodiment's bf my invention Whichis of abroad concept. 7

I claim: I V 1. In a method of concentratin'g and purifying a tox-oid selected from the group consisting of tetanus and diphtheriatoxoi-ds from a dilute acqueoussolution thereof,

the steps comprising adding to said solution a soluble vitreous alkali-metal phosphate having an :MzO/BzGs mole ratio lying between 1.0 and 1.66, Where -Mwsi-gni fies'an alkali metal, lowering the pH of the solution" to precipitatethe toxoid complex, separating the; precipitate from the solution and dissolving-saidprecipitate in :an alkaline solution having a pH of from about 7;7 to.8.0.

' 2.'In a method of concentrating andpurifying tetanus toxoid from dilute aqueous solutions thereof, thesteps comprising adding-to said solution ;a soluble vitreous alkali-metal. phosphate having an MzO/PaOs mole ratio lying between 1.0 and 1.66, where M signifiesan" alkali inetahlowering thepH of the solution toj precipitate thetoxoidcomplex, separating the. precipitate from the solution and dissolving said precipitate in an alkaline solution having a pH of from about 7.7 to 8.0.

-3. In a method of concentrating, andpurifying diphtheria toxoid from dilute aqueous solutions thereof,- the steps comp-rising adding to said solution asoluble vitreous alkali-metal phosphate having anMzO/PzGs mole ratio lying between .1;0 and 1.66, where M signifies an alkali metal, lowering the pH- of the solution to precipitate the toxoid' complex, separating the precipitate from the solution and dissolving saidzprecipitatein an alkaline 7 solution havingia pH of from about 7.7-to 8.0.

4. In a method of concentrating and purifying tetanus toxoid' from a dilute aqueous solution thereof, the steps comprising adding to said solution sodium 'hexameta phosphate' lowering the pH of-the solutiontol precipitate the toxoid complex, separating the precipitatefrom V the solution and dissolving saidprecipitate -in an alkaline solution having a pH of from about 7.7 to 8.0. V -5.-In-a method of concentrating and purifying diphtheria toxoid from a dilute. aqueous solution'thereohdhe stem-comprising adding to said solution sodium h'ex-" a m etaph'osphate," lowering I the pH' of the solution to pre- V cipita'te-'-the'-toxoid complexpseparat'ing the; precipitate nem 'the solution and dissolving said precipitate in: an alkaline solution -having a pHof from ab'out'7;7 to 8.0. '6: ;As a neWkompoSition-of matter the complex wof l) a tox oid 'seleeted from the group consisfing of'tetanus. and diphtheriatoxoids with (2)-the anion of a soluble vitreous alkali-metal phosphate h vin an M2O/P2O51mole V ratio -lying 'b'etween' 1.0 and 1166, 'where 'M "signifies an alkalimet'al, fo'rrnedby' the "addition of said phosphate {7. new composition of matt'er according to. claim i6,inj'which"the'toxoid -i's-tetanus tox-oid.

c J 8. 'Afnew "composition of matter according to acl'aini 6, in whichthe toxoid-is diphtheri'aitoxoid. V V 9. As a' newcompjosition-of matter the'hexametaphos-' phate complex'of tetanus toxoid.

"10." As a new composi- Yon ofmatterthe hexametaphosphate complexor diphtheria toxo'id.

References Cited in the file of this patent UNITED STATES PATENTS Wilson Oct. 4, 1938 OTHER REFERENCES Ser. No. 374,084, Reiss (A. P. C.), published May 11, 1943.

Eaton: on Purification and Concentration of Diphtheria Toxin, J. Bacteriology, '01. 31, pp. 347365 (1936).

Eaton: on Purification and Concentration of Diphtheria Toxin, J. Bacteriology, vol. 34, pp. 139-151 (1937).

Hall et 211.: Ind. & Eng. Chem. 1937, vol. 29, No. 14, pp. 421424 and vol. 30, No. 1, pp. 23-26, 1938.

Norlin: on Purification of Diphtheria Toxin and Tooid-Acta Path. Microbiol. Scand., v01. 24, pp. 505-524 (1947).

Wiame: Biochemica & Biophysica Acta, vol. I, 1947.

Lloyd: Progress in Leather Science, 19201945 pub. Brit. Lea. Mfg. Res. Assoc., London, England, pp. 102 103, 1948.

Jacobs: on Concentration of Tetanus ToXoid, Jour. Am. Pharm. Assoc., Sci. Ed., vol. 39, pp. 466471, Au-

10 gust 1950.

Mudd: Annual Review of Microbiology, vol. 8, 1954. 

6. AS A NEW COMPOSITION OF MATTER THE COMPLEX OF (1) A TOXOID SELECTED FROM THE GROUP CONSISTING OF TETANUS AND DIPHTHERIA TOXOIDS WITH (2) THE ANION OF A SOLUBLE VITREOUS ALKALI-METAL PHOSPHATE HAVING AN M2O/P2O5 MOLE RATIO LYING BETWEEN 1.0 AND 1.66. WHERE M SIGNIFIES AN ALKALI METAL, FORMED BY THE ADDITION OF SAID PHOSPHATE TO AN AQUEOUS SOLUTION OF SAID TOXOID. 